System.IO.IOException : Stream was too long.

[dfengpo]

using var outputStream = new MemoryStream();
var processor = FFMpegArguments.FromFileInput(filePath)
.OutputToPipe(new StreamPipeSink(outputStream), opt =>
{
opt.WithAudioSamplingRate(sampleRate);
opt.ForceFormat("s16le");
});
processor.ProcessSynchronously();

The line processor.ProcessSynchronously() throw System.IO.IOException Stream was too long.
But my audio.mp3 size is 330mb.
How solve it?